Expression of Xenotropic Murine Leukemia Viruses

Abstract

The possibility that env gene products of endogenous murine leukemia viruses might function as determinants of normal cellular differentiation or in cell-cell communication has been suggested by several lines of investigation. First, the G_IXgp70 molecule of strain 129 mice was found to behave as a differentiation alloantigen of T cells in that it was expressed in high levels on thymocytes but not on peripheral T cells (Stockert et al. 1971). Second, it was observed that while gp70 antigens could be found in many body tissues, particularly high levels were detected in certain anatomic sites such as the seminal vesicles and gall bladder epithelium (Lerner et al. 1976). Third, expression of gp70 on the surface of lymphocytes was shown to be augmented following stimulation with antigens or mitogens (Wecker et al. 1977; Moroni and Schumann 1975). Finally, it has been reported that some humoral and cellular immune responses could be inhibited in vitro and in vivo by anti-gp70 antibodies (Moroni and Schumann 1977; Theofllopoulos et al. 1981).